Yes, you can delete them and they will regenerate as needed. Not sure what the exact purpose of those files are (perhaps related to the in-game advertising facility), but you can delete anything in your user files and the game will still run.

The reason I asked is I'm wondering if there's a file or folder that would be causing this recent issue.

I've placed a high rise in Sunset Valley... modified it a bit. And things started getting buggy when my Sim(s) returned from China- China, or WA being more the problem than the high rise in SV. I've moved the son of the family into that high rise and made him the active Sim. Now, when I enter buy/build mode while on the lot it never gets back to live mode. I just sit there and watch the bloody timex icon. The music still plays. I'm able to build and everything appears normal until I click live mode then... freeze, sort of. I can't do anything but move the timex icon. I've waited minutes, which just isn't right.

Prior to that, after returning from China I did a little file swapping since things started getting buggy. I removed the current Sims 3 file to the desktop, started the game to regenerate new files then replaced old with new, leaving out the Saved Sims that I had downloaded and a HiddenPackages.ini file that contained EA lots I have hidden in the lot bin.

So... wondering if there's a file(s) that may be causing this issue? Thanks.

ejnarts1, please edit your previous posts if you have something to add, instead of creating new posts. That just makes the forum easier to read.

Yes, further to what the Wiki article says, anything in the user files folder can be deleted, and will regenerate if needed for the game to run.

Of course, if you delete your saves (or part of a save), or any CC (in the DCCache, mods, Saved Sims or Library folders) then the folders will regenerate as the game needs them, but the files inside will not. After all, the game doesn't need your saves and custom content! (The exception is the Mods folder, which the game will never generate- you have to create that yourself.)

With the problems you are having, delete the cache files and World Caches as indicated in the guide:http://www.simswiki.info/wiki.php?t...1_Refresh_cache
(I think the advice for mac users to not delete the World Caches is erroneous; it sounds as though the user who had issues had damaged their DCCache files, which would give the errors indicated)
If the problem is still occurring then backup and test without custom content (remove the mods and DCCache folder) to see if you still get the issue.